Supplementary Material for: Renal Replacement Therapy for Prevention of Contrast-Induced Acute Kidney Injury: A Meta-Analysis of Randomized Controlled Trials

<i>Background:</i> Contrast-induced acute kidney injury (CI-AKI) is an important cause of acute renal injury. Several clinical trials using renal replacement therapy (RRT) for prevention of CI-AKI yielded conflicting results. We performed a meta-analysis to assess the efficacy of prophylactic RRT on CI-AKI. <i>Methods:</i> Randomized controlled trials on CI-AKI using RRT were identified without language restriction in Cochrane library, Pubmed and Embase. Data extracted from literature were analyzed with Review manager and Stata software. <i>Results:</i> Nine randomized controlled trials involving 751 patients were included. Heterogeneity was found across trials (p &lt; 0.00001). A random effect model was used to combine the data. RRT reduced the risk of CI-AKI by 26% compared with the control group, but statistical significance was not reached (risk ratio (RR) 0.74, 95% CI 0.35–1.60, p = 0.45). Subgroup analysis of modality indicated that hemodialysis was ineffective in reducing the risk of CI-AKI (RR 1.21, 95% CI 0.63–2.32, p = 0.57), while CRRT decreased the incidence of CI-AKI (RR 0.22, 95% CI 0.07–0.64, p = 0.006). Subgroup analysis according to the CKD stage did not record heterogeneity across trials. RRT increased the odds of CI-AKI in CKD stage 3 patients (RR 1.53, 95% CI 0.07–0.64, p = 0.01), but decreased the occurrence of CI-AKI in patients with CKD stage higher than 3 (RR 0.74, 95% CI 0.35–1.60, p = 0.45). The pooled RR of the need for permanent dialysis demonstrated an insignificant trend towards benefit in patients treated with RRT (RR 0.61, 95% CI 0.26–1.40, p = 0.24). RRT reduced in-hospital mortality compared with control group (RR 0.33, 95% CI 0.14–0.77, p = 0.01). <i>Conclusion:</i> RRT fails to reduce the incidence of CI-AKI in CKD stage 3 patients, but may be beneficial in patients with more advanced renal function. CRRT is more effective than hemodialysis for prevention of CI-AKI. RRT is effective in reducing the in-hospital mortality of CI-AKI patients.